This planet gives a glimpse of what Earth could look like in the future

The newly discovered planetary system consists of a white dwarf about half the mass of our sun and an Earth-like planet in an orbit twice the size of Earth's current path around the sun.

In Short

• This discovery provides valuable insights into stellar evolution
• The sun will expand into a red giant in about 5 billion years
• It will likely engulf the inner planets. including Earth

In a groundbreaking discovery, astronomers from the University of California, Berkeley have identified an Earth-sized planet orbiting a white dwarf star approximately 4,000 light-years away in the Milky Way galaxy.

This finding, published in the journal Nature Astronomy, offers a glimpse into a possible future scenario for our own solar system.

The newly discovered planetary system consists of a white dwarf about half the mass of our sun and an Earth-like planet in an orbit twice the size of Earth's current path around the sun. This configuration closely mirrors predictions for the fate of the Earth-sun system billions of years from now.

Lead researcher Keming Zhang, now at UC San Diego, explains that while Earth may only remain habitable for another billion years due to the sun's increasing heat, this discovery shows that planets can potentially survive their star's red giant phase.

The team first detected the system in 2020 through a microlensing event, where the gravity of the distant system magnified light from a background star. Follow-up observations using the Keck II telescope in Hawaii in 2023 confirmed the nature of the host star as a white dwarf.

This discovery provides valuable insights into stellar evolution and its effects on orbiting planets. As our sun expands into a red giant in about 5 billion years, it will likely engulf the inner planets.

Earth might survive by migrating to a more distant orbit, but would be rendered uninhabitable long before then.

Jessica Lu, associate professor of astronomy at UC Berkeley, emphasises the significance of finding a planet that survived its star's red giant phase, even if it's no longer in the habitable zone.

The research team's innovative use of adaptive optics and AI techniques to analyze microlensing events has opened up new possibilities for studying distant star systems.

This approach complements traditional exoplanet detection methods and may reveal more exotic planetary configurations in the future.

As we contemplate Earth's long-term fate, Zhang suggests that humanity might find refuge on the moons of outer planets like Jupiter and Saturn, which could become habitable as the sun expands.

This discovery not only sheds light on our cosmic neighborhood but also prompts us to consider the far-reaching implications of stellar evolution on planetary habitability